Question

A differential band brake as shown in figure, has torque capacity of 3000 N-m. The thickness of the steel band is 3 mm and the maximum tensile stress in the band is 50 N/mm${}^2$. The coefficient of friction betwenn the friction lining and the brake drum is 0.25. Caluculates width of the band.

• A. 103.5 mm
• B. 107.20 mm
• C. 105 mm
• D. 102.70 mm

Answer 1

The correct option is D 102.70 mm

$(T_1-T_2)\times 0.3=3000$

$T_1-T_2=10000......\left(1\right)$

$\frac{T_1}{T_2}=e^{(0.25\times 4\pi /3)}$

$T_1=2.85T_2......\left(2\right)$

$\text{From (1) and (2)}$

$T_1=15405.4N$

$T_1={\sigma }_b\times W\times t$

$15404.4=50\times W\times 3$

$W=102.7mm$